package org.apache.solr.search.function;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import org.apache.lucene.index.IndexReader;

import java.util.Map;
import java.io.IOException;

/**
 * Pass a the field value through as a String, no matter the type
 * 
 **/
public class LiteralValueSource extends ValueSource {
	protected final String string;

	public LiteralValueSource(String string) {
		this.string = string;
	}

	/** returns the literal value */
	public String getValue() {
		return string;
	}

	@Override
	public DocValues getValues(Map context, IndexReader reader)
			throws IOException {

		return new DocValues() {
			@Override
			public String strVal(int doc) {
				return string;
			}

			@Override
			public String toString(int doc) {
				return string;
			}
		};
	}

	@Override
	public String description() {
		return "literal(" + string + ")";
	}

	@Override
	public boolean equals(Object o) {
		if (this == o)
			return true;
		if (!(o instanceof LiteralValueSource))
			return false;

		LiteralValueSource that = (LiteralValueSource) o;

		if (!string.equals(that.string))
			return false;

		return true;
	}

	public static final int hash = LiteralValueSource.class.hashCode();

	@Override
	public int hashCode() {
		return hash + string.hashCode();
	}
}
